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Astronomy (General/Chat)

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  • Astronomy Picture of the Day -- Simeis 147: Supernova Remnant

    10/09/2012 3:52:11 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 09, 2012 | (see photo credit)
    Explanation: It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147 (S147). Also cataloged as Sh2-240, it covers nearly 3 degrees or 6 full moons on the sky. That's about 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. Anchoring the frame at the right, bright star Elnath (Beta Tauri) is seen towards the boundary of the constellations Taurus and Auriga, almost exactly opposite the galactic center in planet Earth's sky. This sharp composite includes image data taken through a narrow-band filter to highlight emission from hydrogen...
  • Astronomy Picture of the Day -- Spherical Planetary Nebula Abell 39

    10/08/2012 8:17:39 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 08, 2012 | (see photo credit)
    Explanation: Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a planetary nebula, formed as a once sun-like star's outer atmosphere was expelled over a period of thousands of years. Still visible, the nebula's central star is evolving into a hot white dwarf. Although faint, the nebula's simple geometry has proven to be a boon to astronomers exploring the chemical abundances and life cycles of stars. In this deep image recorded under...
  • First Scoopful [Martian Soil] a Success [For "Curiosity'}

    10/08/2012 3:49:23 PM PDT · by BenLurkin · 13 replies
    nasa ^ | Mon, 08 Oct 2012 07:52:13 AM PDT
    On the mission's 61st Martian day, or sol (Oct. 7, 2012), NASA's Mars rover Curiosity used its soil scoop for the first time, collecting a scoopful of sand and powdery material at the "Rocknest" site. Imaging verified collection of the sample. The collected material will be used for cleaning interior surfaces of the rover's sample-handling mechanism. It will be held and vibrated inside each chamber of the mechanism before the material is discarded. Curiosity's Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device, on the robotic arm, includes the scoop and the mechanism for sieving and portioning samples of...
  • Weather On Mars Surprisingly Warm, Curiosity Rover Finds

    10/06/2012 9:54:06 PM PDT · by FreedomOfExpression · 27 replies
    Space.com ^ | 10/1/2012 | Space.com staff
    NASA's Mars rover Curiosity is enjoying some nice, warm weather on the Red Planet — and spring hasn't even come to its landing site yet. Curiosity's onboard weather station, which is called the Remote Environment Monitoring Station (REMS), has measured air temperatures as high as 43 degrees Fahrenheit (6 degrees Celsius) in the afternoon. And temperatures have climbed above freezing during more than half of the Martian days, or sols, since REMS was turned on, scientists said. These measurements are a bit unexpected, since it's still late winter at Gale Crater, the spot 4.5 degrees south of the Martian equator...
  • Astronomy Picture of the Day -- The Same Color Illusion

    10/06/2012 9:43:54 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | October 07, 2012 | (see photo credit)
    Explanation: Are square A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The above illusion, called the same color illusion, illustrates that purely human observations in science may be ambiguous or inaccurate. Even such a seemingly direct perception as relative color. Similar illusions exist on the sky, such as the size of the Moon near the horizon, or the apparent shapes of astronomical objects. The advent of automated, reproducible, measuring devices such as CCDs have made science in general and astronomy in particular less...
  • Astronomy Picture of the Day -- At the Heart of Orion

    10/06/2012 1:07:39 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 06, 2012 | (see photo credit)
    Explanation: Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta 1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a recent dynamical study indicates that runaway stellar collisions at an earlier...
  • Cosmic Journeys: The Search For Earth-Like Planets

    10/05/2012 6:07:28 PM PDT · by SunkenCiv · 28 replies
    YouTube ^ | January 8, 2010 | Uploaded by SpaceRip
  • Astronomy Picture of the Day -- Aurora and Fireball Over Norway

    10/05/2012 4:40:53 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | October 05, 2012 | (see photo credit)
    Explanation: What's happening behind that mountain? A convergence of variable sky spectacles. One night in mid-September near Tromsø, Norway, high red aurora could be seen shimmering through lower green aurora in a way that created a striking and somewhat unusual violet glow. Suddenly, though, the sky flashed with the brightest fireball the astrophotographer had ever seen, as a small pebble from outer space violently crashed into the Earth's atmosphere. The glow illuminated the distant mountain peak known as Otertinden of the Lyngen Alps. The bright meteor, which coincidently disappeared behind the same mountain, was also reflected in the foreground Signalelva...
  • Astronomy Picture of the Day -- NGC 7293: The Helix Nebula

    10/05/2012 4:40:35 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | October 04, 2012 | (see photo credit)
    Explanation: A mere seven hundred light years from Earth, in the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution. A total of 58 hours of exposure time have gone in to creating this deep view of the nebula. Accumulating narrow band data from emission lines of hydrogen atoms in red and oxygen atoms in blue-green hues, it shows remarkable details of the Helix's brighter inner region, about 3 light-years across, but...
  • The Best Way to Find Aliens: Look for Their Solar Power Plants

    10/04/2012 9:46:47 PM PDT · by LibWhacker · 43 replies
    The Atlantic ^ | 10/4/12 | Ross Andersen
    A team of astronomers is now looking for Dyson Spheres, massive star-scale solar power plants that extraterrestrial hunters hope alien civilizations employIn 1960, mathematician, physicist, and all-around genius Freeman Dyson predicted that every civilization in the Universe eventually runs out of energy on its home planet, provided it survives long enough to do so. Dyson argued that this event constitutes a major hurdle in a civilization's evolution, and that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Astronomers...
  • Earth Is Undergoing True Polar Wander, Scientists Say

    10/03/2012 3:31:34 AM PDT · by SunkenCiv · 40 replies
    EarthSky.org ^ | October 2012 | Deborah Byrd
    Scientists based in Germany and Norway today published new results about a geophysical theory known as true polar wander. That is a drifting of Earth's solid exterior -- an actual change in latitude for some land masses -- relative to our planet's rotation axis. These scientists used hotspots in Earth's mantle as part of a computer model, which they say is accurate for the past 120 million years, to identify four possible instances of true polar wander in the past. And, they say, true polar wander is happening now... The scientists -- including Pavel V. Doubrovine and Trond H. Torsvik...
  • Astronomy Picture of the Day -- Goat Aurora Over Greenland

    10/03/2012 3:19:15 AM PDT · by SunkenCiv · 21 replies
    NASA ^ | October 03, 2012 | (see photo credit)
    Explanation: Sometimes it's hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it. As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand. Even without the aurora, the sky would be notable for...
  • Astronomy Picture of the Day -- An Ancient Stream Bank on Mars

    10/02/2012 3:33:37 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 02, 2012 | (see photo credit)
    Explanation: Fresh evidence of an ancient stream has been found on Mars. The robotic rover Curiosity has run across unusual surface features that carry a strong resemblance to stream banks on Earth. Visible in the above image, for example, is a small overhanging rock ledge that was quite possibly created by water erosion beneath. The texture of the ledge appears to be a sedimentary conglomerate, the dried remains of many smaller rocks stuck together. Beneath the ledge are numerous small pebbles, possibly made smooth by tumbling in and around the once-flowing stream. Pebbles in the streambed likely fell there as...
  • Astronomy Picture of the Day -- Introducing Comet ISON

    10/01/2012 3:46:01 AM PDT · by SunkenCiv · 6 replies
    NASA ^ | October 01, 2012 | (see photo credit)
    Explanation: Could this dim spot brighten into one of the brightest comets ever? It's possible. Alternatively, the comet could break up when it gets closer to the Sun, or brighten much more modestly. Sky enthusiasts the world over are all abuzz, though, from the more optimistic speculations -- that the newly discovered C/2012 S1 (ISON) could develop a spectacular tail or briefly approach the brightness of the full Moon toward the end of 2013. Comet ISON currently is very faint but is just visible at magnitude 18 in the above image. The comet, discovered just over a week ago from...
  • How to See Uranus in Telescopes This Weekend

    09/30/2012 9:12:53 PM PDT · by Jack Hydrazine · 62 replies
    Space.com via Yahoo.com ^ | 28SEP2012 | Geoff Gaherty
    The planet Uranus reaches opposition on Saturday (Sept. 29). This means that Uranus is directly opposite the sun in the sky. Uranus rises will rise as the sun sets, and set as the sun rises. It will be highest in the sky at local midnight, roughly 1 a.m. if you are on Daylight Saving Time. Uranus was discovered accidentally by William Herschel on the night of March 13, 1781. All the other planets had been known since prehistoric times, so this was a major discovery in its time, and made Herschel famous.
  • Astronomy Picture of the Day -- A Galaxy Collision in NGC 6745

    09/30/2012 4:03:09 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | September 30, 2012 | (see photo credit)
    Explanation: Galaxies don't normally look like this. NGC 6745 actually shows the results of two galaxies that have been colliding for only hundreds of millions of years. Just off the above digitally sharpened photograph to the lower right is the smaller galaxy, moving away. The larger galaxy, pictured above, used to be a spiral galaxy but now is damaged and appears peculiar. Gravity has distorted the shapes of the galaxies. Although it is likely that no stars in the two galaxies directly collided, the gas, dust, and ambient magnetic fields do interact directly. In fact, a knot of gas pulled...
  • Astronomy Picture of the Day -- NGC 7023: The Iris Nebula

    09/29/2012 6:53:10 PM PDT · by SunkenCiv · 15 replies
    NASA ^ | September 29, 2012 | (see photo credit)
    Explanation: Like delicate cosmic petals, these clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula and dutifully cataloged as NGC 7023 this is not the only nebula in the sky to evoke the imagery of flowers. Still, this remarkable image shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the...
  • Modeling the Riddle of the Sun’s Explosive CME’s

    09/28/2012 2:18:54 PM PDT · by Ernest_at_the_Beach · 2 replies
    watts Up With That? ^ | September 27, 2012 | Anthony Watts
    DURHAM, N.H. — Four decades of active research and debate by the solar physics community have failed to bring consensus on what drives the sun’s powerful coronal mass ejections (CMEs) that can have profound “space weather” effects on Earth-based power grids and satellites in near-Earth geospace.In a paper just published in Nature Physics, an international team of space scientists, including a researcher from the University of New Hampshire’s Space Science Center (SSC), explains the mysterious physical mechanisms underlying the origin of CMEs. Their findings, based on state-of-the-art computer simulations, show the intricate connection between motions in the sun’s interior and...
  • Massive Eltanin Meteor 2.5 million years ago set off mass tsunami, changed the climate?

    09/28/2012 11:55:36 AM PDT · by Ernest_at_the_Beach · 13 replies
    JoNova ^ | September 21st, 2012 | Joanne
    From the file of “Things that would really be catastrophic”. Did a meteor have a role in a major shift in Earth’s Climate?The start of the Quaternary period (2.588 million years ago, where the Pliocene became Pleistocene) coincides with evidence of a mega tsunami in the South Pacific.The Eltanin Meteor fell into the South Pacific 2.5 million years ago setting off a (likely) tsunami that was hundreds of meters high and theoretically pushed mass material into the atmosphere which may have contributed to the cooling the globe had already started on. This meteor was hard to detect because it hit...
  • Astronomy Picture of the Day -- APOD: 2012 September 28 - Stars in a Dusty Sky

    09/28/2012 4:06:50 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | September 28, 2012 | (see photo credit)
    Explanation: Bright star Markab anchors this dusty skyscape. At the top right corner of the frame, Markab itself marks a corner of an asterism known as the Great Square, found within the boundaries of the constellation Pegasus, the flying horse. The wide and deep telescopic view rides along for some 5 degrees or about 10 times the angular diameter of the Full Moon, with blue reflection nebulae scattered around the scene. And even though this line-of-sight looks away from the plane of our Milky Way galaxy, it covers a region known to be filled with nearby molecular clouds. The associated...